1. Field of the Invention
The present invention relates to a press-fit contact in which press-fitting into a through-hole of a printed circuit board effects an electrical connection.
2. Related Art
Conventionally, for a connector that is to be mounted on a printed circuit board, contacts for electrical connection to a circuit in the printed circuit board are provided and fixed in place by soldering. However, in recent years, from the viewpoint of solder-free connection or operating efficiency, connectors using press-fit contacts have come to be used.
Such a press-fit contact 10, as shown in FIGS. 7A, 7B, and 7C, is punched out of a sheet of material, and includes an introduction portion 10a for introducing the contact 10 into a through-hole 11a of a printed circuit board 11, a press-fit portion 10b, an expanded portion 10c, and a contact portion 10d. The press-fit portion 10b is formed between the expanded portion 10c and the introduction portion 10a, and like a sewing needle, configured by arc portions 10e projecting along both sides in the shape of an arc so as to form an elliptical slit 10f at the center portion as well as form its edge portions. As shown in FIG. 8, the expanded portion 10c is fitted and fixed in a fixing hole 12a of an insulating housing 12 made of synthetic resin (for example, see JP-A-2005-158507).
Multiple press-fit contacts 10 fitted in the insulating housing 12 are press-fitted into through-holes 11a of the printed circuit board 11 respectively. The arc portions 10e of the press-fit portions 10b of the press-fit contacts 10 are compressed and deformed so that the reaction force causes the arc portions 10e to press against the walls of the through-holes 11 and effect a secure electrical connection.
However, in the conventional press-fit contact 10, as shown in FIG. 7C, the press-fit portions 10b of adjacent press-fit contacts 10, 10 are arranged in alignment in a direction of expansion of the press-fit portion 10b projecting in the shape of an arc. Accordingly, the through-holes 11a of the printed circuit board 11 are also arranged in alignment in the same direction. Therefore, when press-fit contacts 10 to be mounted in a high-density manner are arranged with their pitches narrowed, the pitches between the through-holes 11a are also brought into close proximity with each other, and as a result, contact pressure in the press-fitting of the press-fit portions 10b is generated simultaneously and is concentrated between the through-holes 11a, 11a, causing strain within the board and causing glass fibers of the board to peel.